1. Field of the Invention
The present invention relates to a heat exchanger which can be effectively applied to a radiator for a large construction machine, such as a bulldozer, a power shovel, etc., and for an agricultural machine such as a tractor, etc.
2. Description of the Related Art
A large construction machine, such as a bulldozer, a power shovel, etc., or an agricultural machine such as a tractor, etc. (hereinafter, there machines are generally referred to as special vehicles) are often used in an environment where comparatively large materials, such as gravel, are scattered. Thus, it is highly probable that a radiator is damaged by scattered materials, such as gravel, coming into collision therewith.
Accordingly, as shown in FIG. 5, a radiator for a special vehicle is constituted by a single large radiator having a plurality of heat exchanger units 4 arranged in parallel, which are each comprised of tubes, fins and header tanks, etc. Thus, the heat exchanger units 4 can be replaced or repaired independently of one another to thereby increase the maintainability of the radiator.
A special vehicle is subject to much larger vehicle vibration than an ordinary vehicle such as a passenger automobile, etc. In addition, in a special vehicle, the heat exchanger units must be easily assembled and disassembled. To this end, at present, the adjacent heat exchanger units are spaced at a distance large enough to prevent interference of the adjacent heat exchanger units and to enhance the mounting/demounting efficiency.
However, because the above-mentioned radiator is provided with comparatively large spaces 7 between the adjacent heat exchanger units 4, as shown in FIG. 6, cooling air passes through the spaces 7, so that the amount of cooling air that contributes to a heat exchange is reduced, thus resulting in deterioration of the heat exchanging efficiency (cooling efficiency).